On average, listings lease in the $10's per square foot per year. The St. Charles County region is going through a an increase in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 3% increase in rent.
In the last 90 days, 82 listings have been made available, so you'll want to check back regularly for new listings. About 1% of the office spaces in the St. Charles County are subleases, so you will probably need to sign a longer term lease with the landlord directly. There aren't many listings below 2,000 square feet posted, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,500 sqft. Most buildings in this area are around 1 floors. Most buildings in this market were built in 2000 and are Class B.